The main purpose of this study was to ascertain whether or not the cells are functionally similar throughout the gland, and how transformation mechanism with cytoskeletal components is related to the distribution of ezrin molecules and chloride channel. In this study, the specimens were processed with cryofixation method showed good morphological preservation and retention of soluble components at the light and electron microscopic level. To suppress severe ice-crystal damage or loss of their immunocytochemical properties, stomach tissues from ad libitum-fed or starved rats were prepared with rapid freezing followed by freeze-substitution for light microscopy, and with high pressure freezing for electron microscopy. The transformable structure of parietal cell was examined between the active and resting phases of acid secretion. These structures were the dilated intracellular canaliculi, including numerous microvilli in the secreting phase, and the developed tubulovesicles in apical cy
… Moretoplasm at resting phase. The immunohistochemical staining with anti-alpha- or beta-subunits of H^+・K^+-ATPase antibodies was localized on the cells from both phases. Labeling was more intense and clear on the membranes of intracellular canaliculi, microvilli and tubulovesicles than that with chemical fixation. The positively stained parietal cells were scattered widely throughout the gland. The cells in the secreting phase located in the upper one third of the gland were densely stained with an anti-phosphorylated ezrin antibody. In the resting phase, the antibody showed a weak reaction. However, the anti-nonphosphorylated ezrin antibody hardly labeled those cells. Anti-chloride channel antibody immunostaining showed a narrow zone of positive reaction around the neck region in the secreting phase. These labelings were observed on the membrane of intracellular canaliculi, microvilli and tubulovesicles. It was concluded that the cells in around the upper one third are more active cells for functional secretion than those of other segments, while parietal cells were distributed throughout the gastric gland. Less